Grant, your FSM diagrams are a lot neater than mine!
My slight frustration with EGs is that they are mostly designed with amplitude control in mind. ADSR is a good general purpose model but there are applications where one needs more unusual behaviour such as return to zero on retrigger, instant transitions, attack commit and non-zero termination.
The stock Super Envelope Generator is pretty flexible but still lacks features.
I'm also interested in better expressive interaction between EG shapes, velocity and aftertouch. Also modifications such as from damper, una corda and sostenuto pedals. A real pity I think is that key release velocity has been so neglected by synth designers as it's dirt cheap to implement and being able to control damping (and other things) by how fast one releases a key would add an extra dimension to expressivity.
My particular problem space at the moment is not in creating complex envelope shapes but in creating relatively simple but unusual ones. I'm working with a setup where every control is backed by a 16-step voltage controlled sequencer with cubic spline interpolation arranged in a circular pattern so there's through-zero C0, C1 and C2 continuity. Generating useful envelope control voltages to drive the interpolator is the goal.
If I drive the interpolator with a linear ramp we get the kind of curves shown below directly...
- Splines.png (28.97 KiB) Viewed 520 times
These fancy curves are easy to create as one can do real-time or slow-mo motion recording and non-real-time editing while seeing and hearing the effects. Plus there are randomization and smoothing facilities but what I'm trying to achieve is a relatively straightforward mechanism for bending that ramp so that for instance more detail is available in the attack phase, it's posssible to sustain and to add controlled amounts of aftertouch modulation in the sustain and release phases. Apart from the aftertouch potentially reducing the CV the general trend is rising - another thing that conventional EGs are not good at.
Being able to loop in the sustain phase would be a bonus as would a dual attack facility so that low velocities can produce slow swells while faster velocities take a more percussive path.
So my FSMs are still in a high degree of flux as I attempt to map a path through this minefield.
This is all only in the monophonic domain at the moment but the ideas could be extended.
My handwriting and freeform drawing have always looked like a spider on crystal meth. If I need to communicate anything to someone else, I depend upon word processors, text editors, drawing packages, etc. I drew those diagrams in DIA, an open-source drawing package. Not as user-friendly as Visio, but good enough for my purposes.
